Absolute-positioned wide characters (CJK, emoji) could paint past the
right edge of a clipped box or the terminal grid, producing output wider
than the column limit. Three fixes:
- Safe-slice after sliceAnsi in clip logic to handle wide char overshoot
- Bounds check in grid write loop to skip chars exceeding grid width
- Width-aware border fill to account for measured corner char widths
Yunfei He
5d532f47d1